Band of Stability: Beta Decay - Online Tutor, Practice Problems & Exam Prep

Band of Stability: Beta Decay

Hey everyone. In this video we're going to take a look at beta decay. Here we're going to say that beta decay happens for isotopes to the left of the band of stability. Here we have our band of stability, which is this green curve and this blue area represents where isotopes that exist that will perform beta decay.

Now we're going to say here a good example is Palladium 107. Here it emits a beta particle in order to become silver 107. Now here we're going to say that those in the blue region, these are isotopes that have an excess of neutrons. Beta decay helps them to convert their neutrons or excess neutrons into protons.

If we look take a look here, we have neutrons over here. So what tends to happen is we're going to drop down a little bit in terms of the number of neutrons and we're going to shift to the right, increasing our number of protons. This allows us to fall within the band of stability and become a more stable isotope.

So just remember to the left of the curve we have beta decay. The whole purpose is to help reduce our number of neutrons, increase our number of protons that we fall within the band of stability.

Band of Stability: Beta Decay Example

Here it says to provide the identity of the daughter nuclide created from the beta decay of magnesium 28. So here we're dealing with magnesium, it's mass numbers 28 and if we look on the periodic table, it's atomic number is 12. It's undergoing beta decay, so it's going to emit an electron and we just need to make sure that our mass numbers are the same on both sides and our number of protons are the same on both sides.

Here we have 28 on the left side, so we need a total of 28 for our mass number. On the product side. The electron contributes nothing to the mass number, so our new isotope has to have 28. Here on the left side we have 12 protons. On the right side we still need to have 12 protons, but here we have a -1. So the number here would have to be 13 because 13-1=12.

Looking on the periodic table, the only element that has an atomic number of 13 is aluminum. So the beta decay of Magnesium 28 produces Aluminum 28, meaning that option D is our final answer.

How many beta decays would it take to transform tungsten-184 into iridium-184?

a) 5                                         

b) 1                                          

c) 3                                               

d) 4

• A. 5
• B. 1
• C. 3
• D. 4

Here’s what students ask on this topic:

What is beta decay and how does it relate to the band of stability?

Beta decay is a nuclear process where an unstable isotope with an excess of neutrons converts a neutron into a proton, emitting a beta particle (an electron) in the process. This transformation helps the isotope move towards a more stable configuration by decreasing the neutron count and increasing the proton count. Isotopes that are located to the left of the band of stability on the nuclear chart are prone to beta decay. The band of stability represents the region where isotopes have a balanced neutron-to-proton ratio, making them stable. Beta decay helps isotopes achieve this balance and fall within the band of stability.

Why do isotopes undergo beta decay?

Isotopes undergo beta decay to achieve a more stable configuration. When an isotope has an excess of neutrons, it is located to the left of the band of stability on the nuclear chart. To move towards stability, the isotope converts one of its neutrons into a proton through beta decay, emitting a beta particle (an electron) in the process. This conversion decreases the neutron count and increases the proton count, helping the isotope achieve a balanced neutron-to-proton ratio and fall within the band of stability.

What happens to the neutron-to-proton ratio during beta decay?

During beta decay, the neutron-to-proton ratio decreases. This is because a neutron in the nucleus is converted into a proton, emitting a beta particle (an electron) in the process. As a result, the number of neutrons decreases by one, and the number of protons increases by one. This shift helps the isotope move towards a more stable configuration by balancing its neutron-to-proton ratio, allowing it to fall within the band of stability.

Can you provide an example of an isotope undergoing beta decay?

An example of an isotope undergoing beta decay is palladium-107 (Pd-107). Palladium-107 has an excess of neutrons and is located to the left of the band of stability. To achieve stability, it undergoes beta decay, where a neutron is converted into a proton, and a beta particle (an electron) is emitted. This process transforms palladium-107 into silver-107 (Ag-107). The neutron count decreases by one, and the proton count increases by one, helping the isotope move towards the band of stability and become more stable.

What is the purpose of the band of stability in nuclear chemistry?

The band of stability in nuclear chemistry represents the region on a nuclear chart where isotopes have a balanced neutron-to-proton ratio, making them stable. It serves as a reference for understanding the stability of different isotopes. Isotopes located within the band of stability have a balanced ratio and are generally stable, while those outside the band are unstable and prone to radioactive decay processes, such as beta decay, to achieve stability. The band of stability helps predict the behavior of isotopes and their tendency to undergo specific decay processes to reach a stable configuration.